Unit 1_Spinal Cord & Meninges

Question 1

Describe the spinal cord.

Answer 1

Major reflex center and conduction pathway between the body and brain.

Begins at the foramen magnum as continuation of the medulla oblongata.

Ends at L1/L2 in adults (42-45cm), L3/L4 in children.

Question 2

How many pairs of spinal nerves do we have?

Answer 2

31

Cervical - 8 (7 vertebrae)

Thoracic - 12 (12 vertebrae)

Lumbar - 5 (5 vertebrae)

Sacral - 5 (5 vertebrae)

Coccygeal - 1 (4 vertebrae)

Question 3

Where does the spinal nerve exit in C1?

Answer 3

C1 spinal nerve exits above C1 vertebrae

Question 4

Where does the spinal nerve exit in C7?

Answer 4

C8 spinal nerve exits below C7 vertebrae/above T1

Question 5

Why is the cervical spine called the cervical enlargement?

Answer 5

The nerve that innervates the diaphragm (C3-C5), keeping us alive is here.

Nerve cell bodies that go on to develop the upper limbs are here (C4-C7).

Question 6

What is the lumbosacral enlargement?

Answer 6

The nerve cell bodies that go on to form the fibers, neurons, nerves innervating the buttox down, abdominal muscles, lower limbs live here.

Question 7

What is the conus medularis?

Answer 7

Found at L1-L2, it’s a tapering/cone of the spinal cord.

Question 8

What is the cauda equina?

Answer 8

Nerve roots that look like a horse’s tail from where the cord stopped at L1-L2 to where they need to go.

Question 9

What is filum terminale (terminal filament)?

Answer 9

Extension off the cord, continue down through the sacral canal and bind down on the sacrum and coccyx.

Question 10

What is the dural sac (dura mater)?

Answer 10

Sac follows, meninges follow, surround the brain all the way down into the spinal cord, the sac holds the cerebrospinal fluid (CSF), protection for the spinal cord, encloses the CSF around S2.

Question 11

What is cauda equina syndrome?

Answer 11

It’s a catch all, bundle of nerve roots that are going to exit right/left side of body, there’s been some sort of damage, which may just be compression from the intervertebral disc pushing on nerve roots.

Question 12

What nerve rootlets support motor?

Answer 12

Anterior/Ventral

Question 13

What nerve rootlets support sensory?

Answer 13

Posterior/Dorsal

Question 14

What nerve structure comes off of the spinal cord itself?

Answer 14

Anterior/Posterior nerve rootlets

Question 15

When nerve rootlets join together, what do they form?

Answer 15

Anterior/Posterior Root

Question 16

What is a bulge that forms on the posterior nerve roots made up of a density of cell bodies affecting general sensation?

Answer 16

Ganglion

Question 17

When the anterior and posterior nerve roots join together, what do they form?

Answer 17

Spinal nerve

Question 18

When the spinal nerve is formed and bifurcates, what does it form?

Answer 18

Posterior ramus and anterior ramus

Become mixed nerves to support motor and sensory function

Question 19

What is derived from within the spinal cord?

Answer 19

The nerve rootlets and fibers

Question 20

What is a branching network of intersecting nerves that form nerve plexuses in the cervical spine, lumbar spine, sacral spine?

Answer 20

Ventral Primary Rami

Question 21

What is a situation when an area of skin which is innervated by fibers off the dorsal root of a single spinal nerve forms a mapping pattern of sensory information?

Answer 21

Dermatomes

Question 22

What is connective tissue membranes that surround and support the spinal cord and the nerve roots, as well as contain cerebrospinal fluid (CSF)?

Answer 22

Meninges

Question 23

What are meninges composed of?

Answer 23

3 layers:

Dura mater (superficial)

Arachnoid mater

Pia mater (deep)

Question 24

What is a superficial space to the dura mater of the spinal meninges?

Answer 24

Epidural space (fat)

Question 25

What is between the arachnoid and pia mater within the spinal meninges?

Answer 25

Subarachnoid space

Where the cerebrospinal fluid flows

Question 26

What is the deepest layer of the spinal meningeal layers that adheres to the spinal cord, continues as the filum terminale and forms denticulate ligaments that bind the cord down laterally to the dura mater?

Answer 26

Pia mater

Question 27

What occurs during spinal anesthesia?

Answer 27

Poke a needle into lumbar epidural fat and bathe the cord with anesthesia

Question 28

What occurs during lumbar puncture CSF?

Answer 28

Retrieve and test cerebrospinal fluid, for ‘itis’ meningitis, can poke a needle distal to L1-L2 (below spinal cord)

Question 29

What is one of the main branches of the subclavian artery?

Answer 29

Vertebral artery (2)

Heads into the transverse foramen at C6, and goes through every cervical vertebrae and then branches off of it to feed the posterior aspect of the spinal cord to form 1 posterior spinal artery.

Question 30

What is the function of the anterior vertebral artery?

Answer 30

1 vertebral artery that runs down the midline of the anterior spinal cord made up of a fusion of the two vertebral artery branches to provide blood supply

Question 31

Where are a collection of veins housed?

Answer 31

In the epidural space, outside the dura housed within the neural arch of the vertebral column, there’s a plexus of veins draining the cord in the fat.